// Copyright 2011-2024 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.security.zynamics.zylib.gui;

import com.google.common.base.Preconditions;
import java.io.File;
import java.io.IOException;
import javax.swing.JFormattedTextField;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;

public class CFilenameFormatter extends JFormattedTextField.AbstractFormatter {
  private static final int MAX_CHAR = 255;

  private final FilenameFilter filter = new FilenameFilter();

  private final File m_directory;

  /**
   * Filter for JFormattedTextField. Ensures valid filenames. Does not work for directories.
   *
   * @param directory Directory where a file with the specified filename is temporarily created for
   *     validation purpose. http://stackoverflow.com/questions/893977/java-how-to-find-out-whether
   *     -a-file-name-is-valid
   */
  public CFilenameFormatter(final File directory) {
    Preconditions.checkArgument(directory.exists(), "Error: Directory must exist.");
    m_directory = directory;
  }

  private boolean isValid(final String string, final int selected) {
    if ((((getFormattedTextField().getText().length() - selected) + string.length()) > MAX_CHAR)
        || (string.indexOf("\\") > -1)
        || (string.indexOf("/") > -1)) {
      invalidEdit();
      return false;
    }

    final File file = new File(m_directory.getPath() + File.separator + string);

    if (!file.exists()) {
      try {
        if (!file.createNewFile()) {
          invalidEdit();
          return false;
        }
        file.delete();
      } catch (final IOException e) {
        invalidEdit();
        return false;
      }
    }

    return true;
  }

  @Override
  protected DocumentFilter getDocumentFilter() {
    return filter;
  }

  @Override
  public Object stringToValue(final String s) {
    return s;
  }

  @Override
  public String valueToString(final Object o) {
    if (o == null) {
      return null;
    }
    return o.toString();
  }

  private class FilenameFilter extends DocumentFilter {
    @Override
    public void insertString(
        final DocumentFilter.FilterBypass fb,
        final int offset,
        final String string,
        final AttributeSet attr)
        throws BadLocationException {
      if (isValid(string, 0)) {
        super.insertString(fb, offset, string, attr);
      }
    }

    @Override
    public void replace(
        final DocumentFilter.FilterBypass fb,
        final int offset,
        final int length,
        final String string,
        final AttributeSet attr)
        throws BadLocationException {
      if (isValid(string, length)) {
        super.replace(fb, offset, length, string, attr);
      }
    }
  }
}
